very thirsty 1998 xj8 any tips please

Not that it's manufacturer recommended but you could try cleaning the injectors with something like Redex, it'll help reduce consumption a little.

Ensure you aren't in sport mode as that'll burn extra fuel, so regular mode and easy does it on the gas peddle. If you observe your instant fuel consumption data on the dash you can monitor how your driving style is affecting things.

Check how much junk you have in the boot, lighter goes further for less juice.

Keep your oil topped up too, your cat will respond in kind. I suggest 'Castrol Edge Sport'. Everything is smooth and efficient on that stuff!

If your looking for a JAG, but fuel economy is an issue, perhaps you should have gone for an X type diesel, comfortable, and  well equiped ( Dont like S and X types my self, just a re badged Mondeo, XJ was the last REAL Jag ! )

Go and hire a big America dodge ram for a weekend 6.0 V12 sort of size you will be glad to get your jag back believe me !!

I have heard that if you fill the tank to full then add half a bottle of red X then drive the car hard for about 10 mins it somehow improves the performance....whether this is true or not I can't confirm, but it came from a man from Halfords

I have achieved 25.8 mpg on the first 700 miles of my recently acquired 2000 XJ8. I must admit a lot of motorway but I have found I get an extra couple of mpg driving on the cruise control, hardly using the accelerator at all.

 

The other way is to have a gas conversion which I had on my last XJ6, This will take about 20,000 miles to pay for itself so if you are doing a large mileage is well worth the investment providing you get a decent system. It will return the equivalent of 34-40 mpg.

 

Hope this helps

Welcome to the Club, John.

 

A steady drive using cruise control is a good tip, and another is not using supermarket fuel, and using a tankful of the best quality forecourt fuel.

 

I have a S Type 2.7D and recently achieved 49.2 mpg on an 80 mile journey using top quality fuel.

 

But I do like to do a bit of driving with the S button switched on!

 

Regards,

 

Peter.

get an old Double Six or jag V12   , carb model, I had one, a 1972 model,    I could get 8 MPG in town, 15 on motorways.       Then go back to your present car!